AL-ULA, Saudi Arabia (AP) – Gulf Arab leaders signed a declaration Tuesday to ease a rift with Qatar, following Saudi Arabia’s decision to end a 3 1/2-year embargo of the tiny energy-rich country that deeply divided regional U.S. security allies and frayed social ties across the Arabian Peninsula.

Saudi Arabia also said it was restoring full diplomatic relations with Qatar, although it was not clear how soon the step would be followed by the United Arab Emirates, Bahrain and Egypt, which had joined the kingdom in isolating the country over its regional policies.

On Monday night, the eve of the Gulf Arab leaders’ summit in the ancient desert city of Al-Ula, the Saudis announced they would open the kingdom’s airspace and borders to Qatar, the first major step toward ending the diplomatic crisis that began in 2017, when the Trump administration was starting to raise pressure on Iran.

It was unclear what, if any, significant concessions Qatar had made before the summit. Still, an immediate shift in tone was palpable as one of Qatar’s Al Jazeera Arabic news Twitter accounts shared photos of the Riyadh and Abu Dhabi skylines on Tuesday following years of critical coverage.

Saudi Foreign Minister Prince Faisal bin Farhan told reporters after the summit that diplomatic relations would be restored in full with Qatar, although no time frame was given.

“We are extremely pleased with having been able to achieve this very important breakthrough that we believe will contribute very much to the stability and security of all our nations in the region,” Prince Faisal said. “We are at a place where everybody is satisfied and happy…the returning of diplomatic relations, flights, etc., all of that will now go back to normal.”

The diplomatic breakthrough followed a final push by the outgoing Trump administration and Kuwait to mediate the dispute. It also came as Saudi Arabia seeks to unify Arab ranks ahead of the incoming administration of President-elect Joe Biden, which is expected to take a firmer stand toward the kingdom and re-engage with Iran.

Saudi Crown Prince Mohammed bin Salman, who embraced Qatar’s emir upon his arrival at the summit, said the region needed to unite and face challenges posed by Iran’s proxies and its nuclear and ballistic missile programs.

He said the declaration signed by Gulf leaders and Egypt “emphasizes Arab and Gulf solidarity and stability, and reinforces the continuity of friendship and brotherhood between our countries.”